BREVITAL SODIUM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BREVITAL SODIUM (BREVITAL SODIUM).
Brevital sodium (methohexital) is a barbiturate that acts as a GABA-A receptor agonist, enhancing chloride ion influx and hyperpolarizing neurons, leading to rapid sedation and anesthesia.
| Metabolism | Hepatic metabolism primarily by CYP2C9 and CYP3A4 to inactive metabolites; less than 1% excreted unchanged in urine. |
| Excretion | Primarily hepatic biotransformation to inactive metabolites (mainly hydroxy-methohexital), with renal excretion of metabolites; less than 1% excreted unchanged in urine. Minor biliary/fecal elimination. |
| Half-life | Terminal elimination half-life: 3–6 hours (mean ~4 hours); prolonged in hepatic impairment, obesity, or with repeated dosing due to redistribution. |
| Protein binding | Approximately 70–90% bound to albumin. |
| Volume of Distribution | Vd: 1.1–2.5 L/kg (mean ~1.5 L/kg). Larger Vd indicates extensive tissue distribution (highly lipophilic), leading to rapid redistribution and short duration after single bolus. |
| Bioavailability | IV: 100%. IM: Not well established; likely >90%. Rectal: Variable, ~50–70% due to first-pass metabolism and incomplete absorption. |
| Onset of Action | IV: Rapid, within 30–60 seconds (one arm-brain circulation time). IM: 2–5 minutes. Rectal: 5–15 minutes. |
| Duration of Action | IV: 5–10 minutes for induction effect (single dose); recovery due to redistribution. IM: 20–40 minutes. Rectal: 30–60 minutes. Longer with continuous infusion or high doses. |
Induction of anesthesia: 1-1.5 mg/kg IV bolus over 15 seconds; maintenance: 0.5-1 mg/kg IV bolus as needed or 50-150 mcg/kg/min IV infusion.
| Dosage form | INJECTABLE |
| Renal impairment | No dosage adjustment required for GFR ≥10 mL/min; for GFR <10 mL/min, reduce dose by 50%. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: reduce dose by 75% or consider alternative. |
| Pediatric use | Induction: 1-2 mg/kg IV; maintenance: 0.5-1 mg/kg IV bolus or 50-150 mcg/kg/min IV infusion. Contraindicated in infants <2 months with stable BSA. |
| Geriatric use | Reduce induction dose by 50% and administer slowly over 60 seconds; maintenance infusion rates at lower end (50-100 mcg/kg/min). |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BREVITAL SODIUM (BREVITAL SODIUM).
| Breastfeeding | Excretion into human milk unknown. M/P ratio not determined. Due to short half-life, minimal transfer expected after a single dose. Caution with repeated doses or prolonged infusion. Monitor infant for sedation, feeding difficulties, or respiratory depression. |
| Teratogenic Risk | Teratogenic potential not fully established in humans. In animal studies, methohexital caused fetal resorptions and malformations at maternally toxic doses. First trimester: Avoid unless essential; risk of neural tube defects cannot be excluded. Second trimester: Limited data, but may cause fetal depression if used near delivery. Third trimester: Crosses placenta; may cause neonatal respiratory depression, hypotonia, and prolonged sedation. Use only if clearly needed with lowest effective dose. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Known hypersensitivity to barbiturates","Porphyria (may precipitate acute attacks)","Severe respiratory insufficiency","Status asthmaticus","Hypovolemic shock or severe hypotension"]
| Precautions | ["Respiratory depression and apnea may occur; resuscitative equipment must be available","Hypotension and bradycardia possible; use with caution in patients with cardiovascular disease","Extravasation causes tissue necrosis; avoid intra-arterial injection","Seizures may occur in epileptic patients","Rapid injection may cause severe respiratory depression"] |
| Food/Dietary | No specific food interactions are documented for BREVITAL SODIUM. However, patients should avoid heavy meals before anesthesia due to risk of aspiration. Do not consume alcohol or grapefruit juice for 24 hours before and after administration, as they may alter drug metabolism and increase sedation. |
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| Fetal Monitoring | Continuous maternal vital signs (blood pressure, heart rate, oxygen saturation) and ECG during administration. Fetal heart rate monitoring during and after procedure, especially if used near delivery. Neonatal assessment for respiratory depression, hypotonia, and sedation post-delivery if used late in pregnancy. |
| Fertility Effects | No specific human data on fertility impairment. Animal studies showed no adverse effects on fertility at subanesthetic doses. Use during early pregnancy for procedures is unlikely to affect fertility, but data limited. |
| Clinical Pearls | BREVITAL SODIUM (methohexital) is an ultrashort-acting barbiturate used for induction of anesthesia and for short procedures. Due to its rapid onset and brief duration, it requires careful titration. It is contraindicated in patients with porphyria. Extravasation causes tissue necrosis; administer only through a secure IV line. It lowers seizure threshold, but can also be used for electroconvulsive therapy (ECT) to induce seizures. Respiratory depression and hypotension are dose-dependent; have resuscitation equipment ready. Avoid in patients with severe hepatic impairment. Coadministration with opioids or benzodiazepines potentiates sedation and respiratory depression. |
| Patient Advice | BREVITAL SODIUM is a potent anesthetic that causes rapid loss of consciousness and should only be administered by trained medical professionals. · You may experience temporary pain or burning at the injection site; report any persistent pain or swelling to your healthcare provider. · Drowsiness, dizziness, and confusion may persist for several hours after the procedure; do not drive or operate machinery for at least 24 hours. · Avoid alcohol and other sedatives for 24 hours before and after the procedure as they may increase side effects. · Inform your doctor if you have a history of porphyria, liver disease, or drug allergies. · If you are pregnant or breastfeeding, discuss the risks and benefits with your healthcare provider. |